Table 3.

Frequencies of CBC patients carrying pathogenic DNA-damage repair pathway and ATM missense mutations

Parameter	All CBC patients (n = 247)		Previous RT (n = 169)		No RT (n = 78)		Carriers versus non-carriers
	n	Percentage	n	Percentage	n	Percentage	OR for CBC after RT	95% CI	p
DDRP mutated	51	21	41	24.3	10	12.8	2.18	1.03–4.62	0.043
All patients with only a pathogenic DDRP mutation	37	15	29	17.2	8	10.3	1.8	0.79–4.17
Patients with both a pathogenic DDRP and an ATM missense mutation	14	5.7	12	7.1	2	2.6	2.90	0.63–13.30
Patients with only an ATM missense mutation	29	11.7	21	12.4	8	10.3	1.24	0.52–2.94

Results for all contralateral breast cancer (CBC) patients, and patients stratified by previous radiation exposure, are presented. Odds ratio (OR) and 95% confidence interval (CI) are given for mutation carriers versus non-carriers to develop radiation-associated breast cancer. DDRP, DNA-damage repair pathway; RT, radiation treatment.